Combustion fumes in industrial fusion ovens are currently either let off directly into the atmosphere, with the problems this entails from the standpoint of both environmental pollution and waste of energy, or go through a filtering stage to be scrubbed, in which event they must first pass through a heat exchanger in which the heat energy of the fumes is extracted in order to cool the same down and enable their mechanical filtering using conventional cap filters.
The heat absorbed by the exchanger can be used directly or indirectly, whereas the waste products extracted from fumes can be disposed of or recycled.
In certain industrial fields, however, for instance when obtaining an enamelling frit, within the aforesaid ceramic field, various ovens need to be used, each of which produces a particular kind of enamel. This means that with current filtering systems for combustion gases, the waste products are mixed and, being different per se, since originating in ovens using likewise different raw materials, there is no way that they can be reused, wherefore the said waste products must be thrown out.
Bearing in mind that a normal ceramic enamelling plant uses twelve ovens and each oven generates some 70 kg/day of waste products carried by the exhaust gases, clearly the amount of raw material wasted is significant and it is extremely important for the same to be recyclable.